Field of the Invention
Embodiments disclosed herein relate to an apparatus for manufacturing semiconductor devices. More specifically, an apparatus for laser annealing semiconductor substrates is disclosed.
Description of the Related Art
Thermal annealing is a commonly used technique in semiconductor manufacturing. A process is generally performed on a substrate, for example implanting or doping of the substrate, and then the substrate is subsequently annealed to improve the properties of the substrate. A typical thermal anneal process includes heating a portion of the substrate, or the entire substrate, to an anneal temperature for a period of time.
During the thermal anneal, the material introduced to the substrate typically migrates through the substrate, but some of the material may volatilize into the vapor space above the substrate within the annealing chamber. The volatiles may include elements such as phosphorus, arsenic, and other potentially toxic elements that must be removed from the vapor space before the chamber can be vented into the environment. Additionally, when thermal annealing substrates using lasers having a high fluence, it is possible that portions of the exposed substrate may ablate and undesirably redeposit on the substrate surface or the optics within the thermal annealing system.
Thus, there remains a need for an efficient and cost-effective apparatus for removing undesired thermal annealing byproducts from a thermal annealing apparatus during processing.